JSFiddle - React, Tailwind, and code Playground

HTML

<form action="#">
Zugangsdaten sollen versendet werden per: <br />
<input type="radio" id="method1" name="deliverymethod_job" value="1"/>
<label for="method1">E-Mail</label> <br />
<input type="radio" id="method1" name="deliverymethod_job" value="1"/>
<label for="method2">Telefax</label> <br />
<input type="radio" id="method3" name="deliverymethod_job" value="3"/>
<label for="method3">Brief</label> <br />
<div id="forms">
    <div id="form-empty" class="form"></div>
    <div id="form-email" class="form">
        <ul>
            <label for="titel_job">Anrede:</label>
            <input type="text" id="titel_job" name="titel_job" /><br />
            <label for="lastname_job">Nachname:</label>
            <input type="text" id="lastname_job" name="lastname_job" /><br />
            <label for="mail_job">E-Mail Adresse:</label>
            <input type="text" id="mail_job" name="mail_job" /><br />
         </ul>
    </div>
    <div id="form-telefax" class="form">
        <ul>
            <label for="titel_job">Anrede:</label>
            <input type="text" id="titel_job" name="titel_job" /><br />
            <label for="lastname_job">Nachname:</label>
            <input type="text" id="lastname_job" name="lastname_job" /><br />
            <label for="fax_job">Telefaxnummer:</label>
            <input type="text" id="fax_job" name="fax_job" /><br />
        </ul>        
    </div>
    <div id="form-brief" class="form">
        <ul>
            <label for="company_job">Firma:</label>
            <input type="text" id="company_job" name="company_job" /><br />
            <label for="titel_job">Anrede:</label>
            <input type="text" id="titel_job" name="titel_job" /><br />
            <label for="firstname_job">Vorname:</label>
            <input type="text" id="firstname_job" name="firstname_job" /><br />
            <label for="lastname_job">Nachname:</label>
            <input type="text" id="lastname_job" name="lastname_job" /><br />
            <label...

CSS

.form{ display: none;}

JavaScript

//Formular interakive Radio Button
var $forms=$('#forms'), speed=600;

$('input[name=deliverymethod_job]').change(function() {
  if ($(this).is(':checked')) {
    $forms
      .find('.form:visible')
      .not('.form:eq('+$(this).val()+')')
      .hide(speed)
      .find('input')
      .prop('disabled', true);
    $forms
      .find('.form:eq('+$(this).val()+')')
      .show(speed)
      .find('input')
      .prop('disabled', false);
  }
}).change();